crayon (n.)

"pencil-shaped piece of colored clay, chalk, etc., used for drawing on paper," 1640s, from French crayon "pencil" (16c.), originally "chalk pencil," from craie "chalk," from Latin creta "chalk, pipe-clay," which is of unknown origin. Not now considered to mean "Cretan earth," as once was believed. It also formerly was regarded as possibly from (terra) creta "sifted (earth)," but de Vaan finds this "semantically uncompelling, since 'clay' is not 'sifted earth', but at most 'fine sand'," and he finds creta more likely to be a cognate with, or a borrowing from, Celtic words for "mud, clay" (Old Irish cre, Welsh pridd, Breton pri).